“Infrastructure for Transport of Multimedia Applications to the End User”

1. “Infrastructure for Transport of Multimedia Applications to the End User” Access Network Architectures and High Speed Access Technologies

2. Summary • What are access network options that would be used by different multimedia services providers to carry the multimedia applications to the end users? • Where we stand regarding deployment of numerous DSL and cable modem technologies? • What are the most suitable DSL technologies and why? • How these technologies are deployed in practice?

3. Summary Contd.. • How much the current infrastructure is ready for them • What are the considerations for the success and acceptance of the end user for delivery of multimedia services over the these technologies.

4. Few questions to gain perspective?? • What is a multimedia application? • What is meant by triple play? • How much you know about access networks and their capabilities? • What is a DSL network? • What is a Cable network? • What is the difference between an ATM and IP network?

5. Application Characteristics from Physical Transport Perspective • Three main features for Physical Transport from an application’s perspective. • Bandwidth required • Delay or Latency accepted • Bit Error Ratio • A suitable access network to provide multimedia application needs to provide sufficient bandwidth, necessary BER and data transport delay

6. Access Networks • Traditional networks are copper loop networks providing POTS telephone service and then Coaxial Cable networks providing broadcast video service • Both of these were analog • Multiplexing different applications was difficult if not impossible • Access networks need to be digital to multiplex applications • Next generation Access networks were digital but lacked sufficient bandwidth for Video applications. • Latest Access Networks provide for the bandwidth but are costly to deploy

7. Dilemma for Access Network Upgradation • Who pays for it? Why a service provider should invest? • Given • multimedia services are not necessarily yet a need in society, & • Subscription is a function of economic development of the society • Societies being economically developed should be able to deploy and subscribe • But • What to do with the existing infrastructure • Societies less economically developed are making green field deployments and can start with Triple play support. But there are not many who have extra money to enjoy the service

8. DSL System Model DSLAM/ATM Switch DSLAM/ATM Switch USB DSL Modem Ethernet DSL Modem Access Network ATM Network Access Network TCP/IP - DHCP etc. (rout. fun.) LAN mini port I/F ATM mini port I/F App. Sp. AL/ PPP-o-ATM IEEE 802.3 MAC TCP/IP RFC 1483 AAL5 ATM IEEE 802.3 MAC ATM ATM AAL5 UTOPIA ATM-TC UTOPIA ATM PHY ADSL PHY ATM-TC ATM-TC Ethernet PHY Ethernet PHY CDC1.1 ATM PHY ADSL PHY ADSL PHY USBD CDC 1.1 ATM-TC USB USB ADSL PHY Access Network ATM Network Access Network USB Cable Centillium CO Chip Centillium CPE Chip

9. HFC Network Headend Headend ATM Network CATV Network CATV Network Cable Modem Cable Modem

10. Observations on HFC Networks • Shared medium like LAN so bandwidth guarantee issue • Return path bandwidth Issue for legacy reasons • Point-to-multipoint signaling issue if using ATM transport over HFC networks

11. Full Rate ADSL • ADSL - Asymmetric Digital Subscriber Line • Supports asymmetric rates on medium loops • Application focus is both business and residential • Typical rates: • 6 Mbps Down /0.5 Mbps Up @ 9 kft • Issues with Full Rate ADSL • Late deployment • dual latency • power consumption • POTS Splitter • coverage

12. Splitterless ADSL Lite • Supports asymmetric rates on long loops • Addresses the main Issues with Full Rate ADSL • single latency • reduced complexity, hence low power consumption • no home rewiring • extended coverage • no POTS splitter • fast retrain procedure

13. SHDSL Technology • SHDSL - Single-pair High-Speed Digital Subscriber Line • Supports symmetric rates; 192, 256, 384, 512 768, 1544 2048 and 2304 kbps on moderate to long loops • Application focus is on business, residential office and telecommuters • Uses Trellis coded PAM line code • Echo cancellation is required as both directions use the same frequency band • Spectrally compatible with other DSL systems with some reach restrictions at different rates • Low symmetric rate may compete with ADSL service • Initially SHDSL service is expected to be costlier than ADSL • Draws from ANSI HDSL2 and ETSI SDSL standards

14. VDSL Technology • VDSL - Very-high-speed Digital Subscriber Line • Supports both symmetric and asymmetric rates on much shorter loops • Application focus is both business and residential • Keyword is “Video Delivery” • Typical rates: • Asymmetric; • 52 Mbps Down /6.4 Mbps Up @ 1 kft • 26 Mbps Down /3.2 Mbps Up @ 3 kft • 13 Mbps Down /1.6 Mbps Up @ 4.5 kft • Symmetric; • 26 Mbps @ 1 kft • 13 Mbps @ 3 kft • 6.5 Mbps @ 4.5 kft

15. DSLAM/ATM Switch DSL Modem Access Network VDSL Technology - Access Network Growth DSLAM/ATM Switch DSL Modem Copper Access Network DSLAM/ATM Switch FTTN - Fiber to the Neighborhood DSL Modem Copper Access Network DSLAM/ATM Switch FTTC Fiber to the Curb Fiber Modem FTTH Fiber to the Home

16. Conclusions

17. Conclusions • Quality multimedia applications would only be possible with VDSL type technologies with new deployments • Issues to be resolved are everywhere in the protocol stack